Once Kastus is defeated, you can break the ice wall in the western tower at ( 82, 15, -69 ) Copy/waypoint 82, 15, -69 and reach Odaufe.
Gather the remaining three planks and together with the first one you used to reach Kastus, form a bridge to cross the large chasm with the blue swirly at ( 119, 19, -139 ) Copy/waypoint 119, 19, -139. The location of the planks are:
( -94, 1, -82 ) Copy/waypoint -94, 1, -82
( -85, 26, -70 ) Copy/waypoint -85, 26, -70
( 87, 25, -68 ) Copy/waypoint 87, 25, -68
Climb down the wall. ( 62, 20, -215 ) Copy/waypoint 62, 20, -215
Talk to a freezing goblin. ( 102, 1, -180 ) Copy/waypoint 101.93, 0.63, -179.92
Kick the snow boulder right next to the goblin.
Jump down the chimney and defeat Ice Maiden D'Ina. ( -75, -47, -287 ) Copy/waypoint -75, -47, -287
Click on the nearby egg twice to break it and spawn A Hatched Ice Dragon. It will stun you and escape. Once you are no longer stunned, click on the egg shards again and Snarf Frostfoot will spawn run towards you. Speak to him to finish the quest.
If you kill the dragon before it has a chance to encase you in ice, the quest becomes bugged and you must re-enter the zone and start the quest from the beginning. Make sure your mercenary and pets are on passive and you have no reactive items equipped.